1. Discovery and gene sequence analysis of GⅡ.17 norovirus in Rhesus monkeys of Guangxi
Yunyun XIN ; Yuanyun AO ; Lili LI ; Jiemei YU ; Jinsong LI ; Lin LIN ; Bing ZHANG
Chinese Journal of Experimental and Clinical Virology 2017;31(6):498-503
Objective:
To analyze the prevalence, genetic structure and evolutionary characteristics of GⅡ.17 norovirus isolated from the fecal samples of rhesus monkeys in Longhu Mountain of Guangxi Zhuang Autonomous Region.
Methods:
A total of 400 stool specimens were collected from wild rhesus monkeys from March to August of 2015. The GⅡ.17 norovirus named as GX213 was identified in fecal samples by high-throughput sequencing technology. Reverse transcription-polymerase chain reaction was used to confirm and screen GX213, as well as amplify its complete gene sequence. Then the sequence and phylogenetic analysis of three ORFs of GX213 were constructed by software MEGA 6.0.
Results:
Two out of 400 fecal samples were positive. The full-length genome of GX213 was 7 565 bp (containing PloyA tail), which was composed of three open reading frames (ORFs): ORF1(10-5112 nt), ORF2(5093-6715 nt)and ORF3(6715-7494 nt), with 20 bp overlapping between ORF1 and ORF2, and 1 bp overlapping between ORF2 and ORF3.Analysis of the complete sequence of GX213 showed that it shared the highest homology with the strain of human GⅡ.17 norovirus CUHK-NS-613 (GenBank ID: KU561248) (99.5% identity), and ORF1 and ORF3 also shared the highest homology with the strain CUHK-NS-613 [99.5% and 99.4% in nucleotide (nt); 99.5% and 99.2% in amino acid (aa), respectively], which was the main cause of human norovirus outbreaks in some regions of Asia from 2014 to 2015. ORF2 sequence analysis showed that it displayed the highest identity (99.4% in nt and 99.8% in aa) to the strain CUHK-NS-491 (GenBank ID: KP698928), only one aa mutation aa245P→S(P1.1 region) was observed in the GX213 VP1 protein. Furthermore, the phylogenetic analysis showed that GX213 was more related to CUHK-NS-613 and CUHK-NS-491 than the strain KM1509 (GenBank ID: KX356908) of GⅡ.17 norovirus recently identified in rhesus monkeys.
Conclusions
GX213 belongs to the human GⅡ.17 norovirus variant causing the norovirus outbreaks from 2014 to 2015. Our research suggests that GⅡ.17 norovirus can infect not only humans but also rhesus monkeys.